Al,

Bolts were AN3-6A, but not of the close tolerance variety... not a bad idea though.  Does Van's sell those?

Mark S.

On Sun, Mar 21, 2010 at 10:53 AM, Al Gietzen <ALVentures@cox.net <mailto:ALVentures@cox.net>> wrote:

    The rivets are aluminum.

    I find this surprising, as well as disappointing.

    I checked the rivets on my RD2-C damper assembly and was able to
    confirm that they were in fact beginning to loosen as evidenced by
    the radial streaks on the damper plate.  I picked four rivets at
    random, approx. 90 degrees apart, and grabbed the shop heads with
    vice grips and tried to spin them.  All four would spin with
    little effort, thus confirming that they were beginning to loosen.
     After a phone call to Tracy, we decided to replace the ring of
    rivets with AN3 bolts, which I've now done.

    One advantage to rivets is that they fill the holes to zero
    tolerance.  The bolts will be MUCH stronger, but I’m wondering
    about the potential for some very small amount of ‘play’ to begin
    with, which would not be a good thing.  I don’t know much about
    steel rivets, but maybe that’s the way to go.

    Mark; what nominal length and grip length on the bolts? Are you
    using standard AN bolts or are there ‘true’ diameter or ‘close
    tolerance’ bolts available.

    Al

    Hum-m-m; I just decided I could change schedules in order to fly
    to the Jean, NV gathering next week. Now I’m wondering whether to
    fly anywhere before changing out the rivets. I’m thinking that
    since I see no movement between flange and plate after 180 hours,
    it should be good for at least a few more hours.